Memory support structure

ABSTRACT

A memory support structure includes a base for physically and electrically connecting to a substrate. When so connected, the memory support structure extends orthogonal to the substrate to a height of at least 2.5 cm. The memory support structure provides at least three sockets for receiving and engaging memory modules so that they extend parallel to the substrate. The memory support structure also includes electrical pathways for electrically connecting the sockets and the base so that a memory module inserted into one of said sockets is electrically connected to the substrate.

BACKGROUND

Blade and other modular computer systems offer limited space into whichcomputer components such as central processing unit (CPU) assemblies(including heat sinks) and memory modules can be arranged, e.g., on amotherboard. If there are memory modules at different interconnectdistances, the most distant memory modules can place a lower limit onmemory bandwidth. On the other hand, close packing of memory modules canmake routing more difficult, both between the CPU and the memory modulesand between the CPU and other devices that the CPU accesses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a memory support structure.

FIG. 2 is a flow chart of a process in accordance with an embodiment.

FIG. 3 is a schematic plan view of a computer (in accordance with anembodiment.

FIG. 4 is a schematic sectional view of a first variant of the node ofFIG. 3.

FIG. 5 is a schematic sectional view of a second variant of the node ofFIG. 3.

FIG. 6 is a schematic sectional view of a third variant of the node ofFIG. 3.

FIG. 7 is a schematic plan view of a computer node in which memory banksare arranged back to back in accordance with an embodiment.

FIG. 8 is a schematic partial sectional view of the node of FIG. 7.

FIG. 9 is a schematic partial sectional view of a computer node havingtwo-sided memory banks in accordance with an embodiment.

DETAILED DESCRIPTION

A system 100 includes a memory support structure 101, shown in FIG. 1.Memory support structure 101 includes a base 102 for connecting to asubstrate 104, sockets 106 for engaging memory modules 108 uponinstallation, and electrical pathways 110 electrically connectingsockets 106 and said base 102 so that memory modules 108, when insertedinto sockets 106, are electrically connected to substrate 104. A process200, flow-charted in FIG. 2, provides for installing support structure101 on substrate 104 so that support structure 101 extends vertically atleast 2.5 centimeters (cm) therefrom. At process segment 202, memorymodules are installed in sockets 106 so that the memory modules extendparallel to substrate 104 and so that at least one of the memory modulesis at least 2.5 cm from the substrate.

Unlike memory bank modules that extend two-dimensionally along asubstrate and hold memory modules orthogonal to the substrate, supportstructure 101 takes advantage of a third dimension to stack memorymodules. Since less substrate area is consumed, other components can bearranged closer to a CPU assembly. Also, to the extent that shortermemory modules can be produced, the design of structure 101 can alloweven closer spacing of components. Electrical connections between memorymodules and a CPU can be short and direct so as to enhance systemperformance. In contrast to existing right-angle memory supportstructures, a greater height accommodates more memory modules andprovides more volume for ventilation.

A computer node 300, shown in FIG. 3, includes a printed-circuit board302 or other interconnect substrate, a CPU assembly 304, and memory bankmodules 311-314. Computer node 300 can be the sole node of a computersystem or one of plural computer nodes in a multi-processor computersystem. In the latter case, computer node 300 can be one of two or morenodes sharing PCB 302, e.g., in a blade system. CPU assembly 304 caninclude a CPU 316, which can be single- or multi-core. In addition, CPUassembly 304 can include packaging for CPU 316 and a heat sink 317.

FIGS. 4, 5, and 6 represent different arrangements of the componentsshown in FIG. 3. As shown in FIG. 4, memory bank 311 includes a memorysupport structure 402 having a base 404 and sockets 411, 412, and 413for securing respective memory modules 421, 422, and 423. Memory supportstructure 402 is dimensioned so that its height above PCB 302 and thedistance of a memory module installed in socket 413 are within 20% ofthe height of CPU assembly 304 (e.g., the top 460 of the heat sink)above PCB 302 since CPU assembly 304 and memory banks 311-314 are likelyto be subject to the same height constraints. In this case, the heightof memory support structure 402 is about 4.2 cm, e.g., between 4.0 cmand 4.6 cm. While support structure 402 holds up to three memorymodules, other embodiments provide for holding up to or four or morememory modules.

Base 404 provides for a surface mount connection to PCB 302. In otherembodiments, other connection technologies are employed to install amemory support structure on a PCB. When installed, memory supportstructure 402 extends orthogonally (vertically, in the orientation ofFIG. 4) from the plane of PCB 302. Sockets 411-413 are oriented so that(when memory support structure 402 is installed on PCB 302) memorymodules 421-423 extend parallel to the plane of PCB 302, as shown inFIG. 4.

Memory support structure 402 includes electrical paths 425 forelectrically connecting to electrical paths 427 of PCB 302 so that CPU316 (FIG. 3) can access memory modules 421-423. In practice electricalpaths 425 can define a common bus shared by sockets 411-413.

Memory banks 312-314 (FIG. 3) are connected in the same manner as memorybank 311. As shown in FIG. 4, memory bank 312 includes a supportstructure 432, a base 434, sockets 441-443 for holding memory modules451-453. Support structure 432 extends orthogonally from PCB 302, whileits memory modules 451-453 extend from sockets 431-433 parallel to PCB302. Memory support structure 432 includes electrical paths 455 forelectrically connecting to electrical paths 457 of PCB 302 so that CPU316 (FIG. 3) can access memory modules 441-443.

Memory banks 311 and 312 are both oriented so that their memory modules421-423 and 451-453 extend to the left in the representation of FIG. 4.Since memory banks 311 and 312 are on opposite sides of CPU assembly304, memory modules 421-423 extend toward CPU assembly 304, whereasmemory modules 451-453 extend away from CPU assembly 304. The opposingorientations relative to CPU assembly 304 has an impact the lengths ofelectrical paths 427 and 457 used to connect memory modules to CPUassembly 304. As is apparent in FIG. 4, electrical paths 427 are longerthan electrical paths 457.

in the variation depicted in FIG. 5, all memory banks, including banks311 and 312 as shown, have memory modules, e.g. modules 421-423 and451-453, oriented so that the memory modules extend away from CPUassembly 304. This arrangement provides for minimum lengths for pathways427 and 457 over which. CPU 316 (FIG. 3) accesses banks 311 and 312.This in turn can lead to shorter memory access times and higherperformance.

In the variation depicted in FIG. 6, all banks, including banks 311 and312, as shown, are oriented so that their memory modules, e.g., memorymodules 421-423 and 451-453, extend toward CPU assembly 304. Thisarrangement provides for room and thus routing flexibility about theheavily trafficked area near CPU 316 (FIG. 3). In the embodiment andvariations of FIGS. 3-6, banks 311 and 314 are on the same side of CPUassembly 304, while banks 312 and 313 are on the opposite side. In theembodiment and variations of FIGS. 3-6, all memory banks are the samedistance from the CPU. No memory banks are arranged behind other memorybanks and connections are not ganged (serialized), which could limitperformance.

A node 700, shown in FIG. 7, includes a PCB 702, a CPU assembly 704including a CPU 706, and memory banks 711-714 and 721-724 (which may bethe same as memory banks 321-324). Memory banks 721-724 are “behind”respective ones of memory banks 711-714, from the perspective of CPUassembly 304. In effect, memory banks are arranged in back-to-backpairs, as indicated for memory banks 712 and 721 in FIG. 8.

Memory modules 731-733 extend from memory support structure 735 ofmemory bank 712 toward CPU assembly 704, while memory modules 741-743extend from memory support structure 745 of bank 722 away from CPUassembly 704. In this arrangement, routing flexibility is providedbetween memory banks and CPU 706, and there is negligible difference inthe distances between the connections 751 and 752 respective to memorybank 712 and memory bank 722. Thus, design flexibility and highperformance are both provided. In alternative embodiments, a pair ofmemory banks can be arranged face-to-face or both can be oriented in thesame direction.

A computer node 900 having a two-sided memory bank 912 is shown in FIG.9. Node 900 includes a PCB board 304 and a CPU assembly 904. Memory hank912 includes a support structure 920 for memory modules 931-933, whichextend toward CPU assembly 904, and memory modules 941-943, which extendaway from CPU assembly 904. An electrical pathway 951 of PCB 904provides CPU assembly 904 access to memory modules 931-933 and 941-943.Node 900 can include two, three, four or more such memory banks.

Herein, a “memory support structure” is a structure with featurespermitting a memory module to be installed so that it is physically andelectrically connected to the support structure. Herein, a “memorymodule” is a module, such as a single-inline-memory module (SIMM) ordual-inline memory module (DIMM) having one or more integrated circuitsin which most of the transistors are devoted to storing information incomputer-readable form. Herein, a memory module has length, height, anddepth dimensions in order of decreasing magnitude. Herein, “extending”is taken relative to a point of attachment; “extending toward” refers toextending from a point of attachment toward some other object such as aCPU assembly.

Herein, a “memory bank” is an assembly of a memory support structurewith memory modules installed therein. Herein, “orthogonally” means“more orthogonal than parallel” and “parallel” means “more parallel thanorthogonal”. The dimensions in which a substrate extends are it lengthand width, while its depth dimension is orthogonal to the length andwidth dimensions. Herein, a “socket” is a feature for physically andelectrically engaging a module so that the module can be installed.Herein, “substrate” encompasses PCBs and, other structures used tophysically support and electrically interconnect components such as CPUsand memory banks.

Herein, a “system” is a set of interacting elements, wherein theelements can be, by way of example and not of limitation, mechanicalcomponents, electrical elements, atoms, instructions encoded in storagemedia, and process segments. In this specification, related art isdiscussed for expository purposes. Related art labeled “prior art”, ifany, is admitted prior art. Related art not labeled “prior art” is notadmitted prior art. The illustrated and other described embodiments, aswell as modifications thereto and variations thereupon are within thescope of the following claims.

1. A system comprising an at least 2.5 cm tall first memory supportstructure including: a base for physically and electrically connectingto a substrate so that said first memory support structure extendsorthogonal to said substrate; sockets for receiving and engaging atleast three memory modules concurrently so that the memory modulesextend parallel to said substrate; and electrical pathways electricallyconnecting said sockets and said base so that a memory module insertedinto one of said sockets is electrically connected to said substrate. 2.A system as recited in claim 1 further comprising a first memory bankincluding said first memory support structure and said memory modulesinstalled therein.
 3. A system as recited in claim 2 wherein said memorymodules include at least three memory modules at different respectivedistances from said substrate.
 4. A system as recited in claim 2 furthercomprising a computer node including: said substrate; a CPU assemblyattached to said substrate, said CPU assembly including a CPU and a heatsink, said heat sink having a top located a first distance of more than2.5 cm from said substrate; said memory bank including said first memorysupport structure, said first memory support structure extending to asecond distance from said substrate within 20% of said first distance.5. A system as recited in claim 4 wherein said node further includes asecond memory bank including a second memory support structure andmemory modules extending parallel to said substrate and in a directionopposite from a direction in which the memory modules of said firstmemory bank extend.
 6. A system as recited in claim 5 wherein said firstand second memory banks are on opposite sides of said CPU assembly.
 7. Asystem as recited in claim 6 wherein said node further comprises thirdand fourth memory banks, said third memory bank being on the same sideof said CPU assembly as said first memory bank, said fourth memory bankbeing on the same side of said CPU assembly as said second memory bank.8. A system as recited in claim 7 wherein said first, second, third, andfourth memory banks are the same distance from said CPU assembly.
 9. Aprocess comprising installing at least three memory modules in a memorysupport structure so that at least one of the memory modules extendsparallel to and at least 2.5 cm from a substrate to which said memorysupport structure is attached.
 10. A process as recited in claim 9further comprising physically attaching and electrically connecting saidmemory support structure to said substrate.
 11. A process as recited inclaim 10 wherein said installing includes installing said memory modulesso that they are aligned with respect to dimensions in which saidsubstrate extends and distributed with respect to a dimension orthogonalto those dimensions.
 12. A process as recited in claim 11 wherein: saidattaching involves attaching at least first and second memory supportstructures on opposite sides of a CPU assembly mounted on saidsubstrate; and said installing includes installing memory modules insaid first and second memory support structures so that the memorymodules installed in said first memory support structure extend in adirection opposite to a direction in which the memory modules in saidsecond memory support structure extend.
 13. A process as recited inclaim 12 wherein said attaching further includes: attaching a thirdmemory support structure to said substrate on the same side of said CPUassembly on which said first memory support structure is located; andattaching a fourth memory support structure to said substrate on thesame side of said CPU assembly on which said second memory supportstructure is located so that said first, second, third, and fourthmemory support structures are the same distance from said CPU assembly.14. A process as recited in claim 13 wherein said installing involvesinserting at least three memory modules into each of said memorysupports.
 15. A process as recited in claim 12 wherein said CPU assemblyhas portion at a maximum distance from said substrate, at least one ofsaid memory modules being installed so that it is within 20% of thatdistance from said substrate.